Mold
Molds are some of the most common asthma triggers. They grow in damp areas with a dead organic food source, such as wood. They reproduce by releasing spores into the atmosphere, which can trigger asthma attacks. The best way to control mold growth is to control moisture in your house. Fix leaking pipes and provide ventilation to damp areas. Mold spores can remain dormant for long periods of time, so make sure to clean moldy areas thoroughly with bleach or an anti-fungal agent.